Add Rigify Widgets to Weight Painted Figure
With Rigify, you need to generate the rig from the meta rig first, before weight painting.

In blender all control widgets etc are also bones, but may or may not be allowed to move the mesh, depending on whether the deform flag is set on them or not (this can be found in the bone properties tab in the properties editor). In the generated rigify rigs, the deform bones are hidden by default, and normally on the third to last layer:

These are the ones you need to weight paint.

You may also find the following (slightly old) link useful:
https://blenderartists.org/t/rigging-with-rigify/673045/2